材料期刊网

研究含石墨(Gr)和氮化硅纳米颗粒金属型搅拌铸造LM16合金的摩擦学性能.在干滑动摩擦条件下分别制备Al?Gr?Si3N4混杂复合材料、Al?Si3N4和Al?Gr纳米复合材料.采用EDS测试技术确保Si3N4纳米颗粒和石墨在铸件中的均匀分布.采用L9正交实验方法进行实验以研究应用载荷(20,30和40 N)和滑动距离(1,2和3 km)对合金摩擦磨损性能的影响.结果表明:与Al?Si3N4纳米复合材料相比,Al?Gr?Si3N4混杂复合材料的磨损率和摩擦因数(COF)分别降低了25%和15%,而Al?Gr纳米复合材料的磨损率和COF很小.混杂复合材料的显微维氏硬度比普通复合材料的提高了14%,而Al?Gr和Al?Si3N4纳米复合材料的显微硬度无明显变化.用扫描电镜对合金磨损表面和次表面的组织进行观察.结果表明,纳米复合材料的主要磨损机理为磨粒磨损,而混杂复合材料的主要磨损机理为磨粒磨损和粘着磨损.方差分析(AVOVA)和F检验用于验证模型的有效性及确定影响磨损率的显著性参数.

The tribological behaviour of gravity die stir cast LM6 alloy with graphite (Gr) and silicon nitride nanoparticles was investigated. Al?Gr?Si3N4 hybrid composite, Al?Si3N4 nanocomposite and Al?Gr nanocomposites were separately fabricated to investigate their frictional and wear characteristics under dry sliding conditions. EDS was used to ensure the uniform presence of nano Si3N4 and graphite in the cast. L9 orthogonal array method was chosen to conduct the experiments to study the effect of different applied loads (20, 30 and 40 N) and sliding distances (1, 2 and 3 km). The results showed that the respective wear rate and coefficient of friction (COF) decreased by 25% and 15% for hybrid composite when compared with those of Al?Si3N4 nanocomposite whereas the wear rate and COF of Al?Gr was found to be very minimal. The micro Vickers hardness of the hybrid composite was 14% more than that of the simple nanocomposite and there was not much notable variation for Al?Gr and Al?Si3N4 nanocomposite materials. Scanning electron microscope was used to analyze the worn surface and subsurface, from which it was noted that the predominant wear mechanisms observed were abrasive for nanocomposite and both abrasive and adhesive mechanism for hybrid composite. Analysis of variance (ANOVA) andF-test were used to check the validity model and to determine the significant parameters affecting the wear rates.